METHANOL CONVERSION TO HYDROCARBONS OVER WO3 HZSM-5 CATALYSTS PREPARED BY METAL-OXIDE VAPOR SYNTHESIS/

Metal oxide vapor synthesis (MOVS) methodology was used to deposit WO3 on the zeolite HZSM-5. Samples I, II, and III of various weight perce ntage-loaded (3.1, 5.4, and 10.8, respectively) WO3 on the HZSM-5 supp ort were prepared. These materials were characterized by powder X-ray diffraction pattern, sorption, chemical analysis, and scanning electro n microscopy. The characterization studies showed good crystalline nat ure of the support, partial inclusion of WO3 particles into the zeolit e cavities, and a uniform deposition of amorphous WO3 over the support . These samples were tested for their catalytic activity in the conver sion of methanol into hydrocarbons. Results were compared with that of pure support under identical conditions. The product selectivity for aromatics over WO3/HZSM-5 catalyst samples was negligible compared wit h the same selectivity observed over pure support, whereas the selecti vity for olefins increased significantly.